I do not believe that McCain will arrest conservative activists. The Democrats will.
As long as conservatives are free to organize at the grassroots level, there is hope. We don't need a conservative president. We just need a president who will leave us free to organize.
The Minutemen exist because Bush tolerated their existence. The Democrats will not tolerate such groups. They will prosecute conservative activists and throw many of our leaders in jail.
Why don't you think McCain would act to stop that, given that he wrote legislation to forbid any such grass-roots people from doing anything to spread their message to the public? Even sending five hundred or more unsolicited letters to people telling them that McCain is a jerk is a felony offense, thanks to Senator McCain.